1. Field of the Invention
The invention relates to the protection to ferrous articles from oxidation and corrosion or the acquisition of a surface excess of carbon transmitted by the atmosphere using a thermochemical treatment including pre-heating the ferrous articles followed by immersion in a coating composition comprising an intimate dispersion or emulsion of a complex of metal oxides in a mixture of organic liquids.
2. Description of the Prior Art
A process for protecting ferrous metals and products is described in Spanish Patent Application Ser. No. 441,498 filed Oct. 3, 1975 for Thermochemical Procedure for Coating of Ferrous Metals. In that application there is disclosed a process for treating ferrous articles to keep them in their natural state of ductility while at the same time preserving them from rust, corrosion and deformation of the ferrite A, B and Y. The procedure comprised
(a) thoroughly mixing the following materials: 300 grams of magnesium oxide, 100 grams of zinc oxide, 50 grams of lead dioxide, 50 grams of lead pentoxide, 100 grams of chromium oxide, 100 grams of aluminum oxide, 150 grams of manganese oxide, 150 grams of cobalt oxide;
(b) thoroughly dispersing or emulsifying the mixture of step (a) in a mixture of 1 liter of neatsfoot oil, 2 liters of African palm oil, 4 liters of transmission oil of 160 or 170 density;
(c) pre-heating the ferrous articles which are to be treated to a temperature of 520.degree. C.;
(d) contacting the pre-heated ferrous articles of step (c) with the mixture of step (b) for a short time, i.e., approximately 30 seconds; and
(e) removing the articles from the mixture of step (b) and allowing them to cool.
The present invention comprises improvements in the foregoing process and products whereby greater penetration of the treatment into the surface of the ferrous metal article is achieved.